In OTTHYMO, the removal efficiency of TSS and TP are defined at the RouteReservoir and LIDs. The pollutant removal will only happen to a part of those objects. For example, the pollutant concentration of the overflow from RouteReservoir and LIDs will not be decreased. When importing OTTHYMO project to VOSWMM, the program will search the corresponding objects in VOSWMM that have pollutant removal. The followings are the places where the pollutant removal will be observed in OTTHYMO and the corresponding VOSWMM objects:

RouteReservoir Outflow Pump: RouteResoirve-NHYD[x]-Outflow
Soakway Pit Underdrain Pump: SoakawayPit-NHYD[x]-Underdrain
Chamber Underdrain
Chamber Outflow
Pump: Chamber-NHYD[x]-Underdrain
Conduit: Chamber-NHYD[x]-Outflow
Pavement Underdrain Pump: Pavement-NHYD[x]-Underdrain
Green Roof Underdrain Pump: GreenRoof-NHYD[x]-Underdrain
Bioretention Underdrain
Bioretention Outflow
Pump: Bioretention-NHYD[x]-Underdrain
Conduit: Bioretention-NHYD[x]-Outflow
Enhanced Swale Underdrain Pump: EnhancedSwale-NHYD[x]-Underdrain
Filter Treated Flow Pump: Filter-NHYD[x]-Treated

where x is the NHYD of the OTTHYMO object.

The program will then find the children nodes of those VOSWMM links that are responsible for pollutant removal and assign the removal efficiency at those nodes. For example, for RouteReservoir, it will be the child of the Pump RouteResoirve-NHYD[x]-Outflow. At the Treatment field of the searched node, in its Treatment Editor, the expression will be assigned as following. Please note: If the searched node already has a treatment expression, the existing expression will be kept.

  • TSS: R = R_TSS/100
  • TP: R = R_TP/100

where R_TSS and R_TP are the Water Quality Removal Efficiency of the OTTHYMO object, for example, the RouteReservoir.